Designation D7056 − 07 (Reapproved 2012) Standard Test Method for Determining the Tensile Shear Strength of Pre Fabricated Bituminous Geomembrane Seams1 This standard is issued under the fixed designa[.]
Trang 1Designation: D7056−07 (Reapproved 2012)
Standard Test Method for
Determining the Tensile Shear Strength of Pre-Fabricated
This standard is issued under the fixed designation D7056; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last reapproval A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1 Scope
1.1 This test method presents the procedures used for
determining the quality of prefabricated bituminous
geomem-brane (PBGM) bonded seams subjected to a shear test It
describes a destructive quality control test used to determine
the integrity of PBGM seams
1.2 This test procedure is intended for PBGM only
1.3 The type of thermal field seaming technique used to
construct PBGM seams include the following
1.3.1 Torch-on—This technique melts two PBGM surfaces
to be seamed by running a flame from a propane torch between
them Pressure is applied on the top or bottom, or both PBGM,
forcing together both surfaces to form a continuous bond
1.3.2 Hot Air—This technique introduces high-temperature
air or gas between two PBGM surfaces to facilitate melting
Pressure is applied on the top or bottom, or both PBGM,
forcing together both surfaces to form a continuous bond
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use It is the
responsibility of the user of this standard to establish
appro-priate safety and health practices and determine the
applica-bility of regulatory limitations prior to use.
2 Referenced Documents
2.1 ASTM Standards:2
D638Test Method for Tensile Properties of Plastics
D5199Test Method for Measuring the Nominal Thickness
of Geosynthetics
E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
3 Terminology
3.1 Definitions of Terms Specific to This Standard: 3.1.1 geomembrane, n—an essentially impermeable
geosyn-thetic composed of one or more syngeosyn-thetic sheets
3.1.2 geosynthetic, n—a planar product manufactured from
bitumen or polymeric material used with soil, rock, earth or other geotechnical engineering related material as an integral part of a man-made project, structure or system
3.1.3 geotextile, n—any permeable textile material used in
foundation, soil, rock, earth, or any other geotechnical engi-neering related material, as an integral part of a man made project, structure, or system
3.1.4 Prefabricated Bituminous Geomembrane (PBGM),
n—a material fabricated in a plant and consisting principally of
non-woven polyester textile, impregnated by a blend of oxi-dized or polymer-modified bitumen incorporating filler
3.1.5 Quality assurance, n—all planned and systematic
actions necessary to provide adequate confidence that an item
or a facility will perform satisfactorily in service
3.1.6 Quality control, n—the operational techniques and the
activities, which sustain a quality of material, product, system,
or service that will satisfy given needs; also the use of such techniques and activities
4 Significance and Use
4.1 The use of PBGM as barrier materials to restrict liquid migration from one location to another in soils has created a need for a standard test method to evaluate the quality of PBGM seams In the case of PBGM, it has become evident that seams can exhibit separation in the field under certain condi-tions Although this is an index type test method used for quality assurance and quality control purposes, it is also intended to provide the quality assurance engineer with suffi-cient seam shear data to evaluate seam quality Recording and reporting data will allow the quality assurance engineer to take measures necessary to ensure the repair of seams with unac-ceptable strength during facility construction, and therefore, minimize the potential for seam separation in service
5 Apparatus
5.1 Tensile instrumentation shall meet the requirements outlined in Test MethodD638
1 This test method is under the jurisdiction of ASTM Committee D35 on
Geosynthetics and is the direct responsibility of Subcommittee D35.10 on
Geomem-branes.
Current edition approved Feb 1, 2012 Published April 2012 Originally
approved in 2004 Last previous edition approved in 2007 as D7056 – 07 DOI:
10.1520/D7056-07R12.
2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 United States
Trang 25.2 Grip Faces—Grip faces shall be a minimum of 50 mm
(2 in.) wide and a minimum of 50 mm (2 in.) in length Smooth
rubber, fine serrated or coarse serrated grip faces have all been
found to be suitable for testing PBGM If needed, the use of a
silicone-coated paper to help holding the PBGM specimen
ends into the grips is recommended The silicone-coated side is
to be used in contact with the PBGM specimen (seeFig 1)
6 Sample and Specimen Preparation
6.1 Seam Samples—Cut a portion of the fabricated seam
sample from the installed PBGM in accordance with the
project specifications It is recommended that the cutout
sample be a minimum of 0.5 m (1.65 ft) wide and a minimum
0.6 m (2 ft) in length with the seam centered in the middle
6.2 Specimen Preparation—Prepare five (5) specimens from
each sample The specimens shall be rectangular and 50 6 0.5
mm (2 6 0.02 in.) wide The length of the specimen shall be
at least 200 mm (8 in.) greater than the width of the seam
Specimens shall be cut such that the seam is perpendicular to
the longer dimension of the strip specimen
6.3 Conditioning—Samples shall be conditioned for 24 h at
21 6 2°C (70 6 4°F) at a relative humidity of 30 % to 55 %
If the relative humidity is between 55 % and 70 %, the samples
shall be conditioned for 48 h The samples shall be conditioned
flat and shielded from the sun
7 Procedure
7.1 Shear Testing—Fully support the test specimen within
the grips across the width of the specimen Secure the grips 50
62.5 mm (2 6 0.1 in.) from each side of the start of the seam
Subject specimens to the shear test (seeFig 2) using a constant
machine crosshead speed of 50 6 2.5 mm (2 6 0.1 in.)/min
The test is complete when the specimen has ruptured
8 Report
8.1 The report shall include the following information:
8.1.1 Report test temperature and humidity
8.1.2 Report the cross head speed used during shear testing
8.1.3 Report each individual specimen width
8.1.4 Report each individual specimen seam length
8.1.5 Report each individual specimen maximum load val-ues If the shear specimen does not rupture, report the elongation at the maximum cross-head travel limitation 8.1.6 Report the average and standard deviation of the maximum load values
8.1.7 Report any other operating detail, as well as any possible incident
8.1.8 If requested, report the maximum shear stress This calculation will require an accurate measurement of thickness for each specimen These measurements should be made in accordance with Test MethodD5199for PBGM
9 Precision and Bias
9.1 Precision3—The precision of this test method is based
on an Interlaboratory study of Test Method D7056-04 con-ducted in 2005 Each of ten laboratories tested three different materials Each laboratory obtained three replicate test results for each material After individual laboratory issues were addressed, the data set analyzed consisted of (at a minimum) replicate information from at least six laboratories for each of the three materials, therefore this study meets the basic criteria set forth in PracticeE691
9.1.1 Repeatability—Two test results obtained within one
laboratory shall be judged not equivalent if they differ by more
than the “r” value for that material; “r” is the interval
representing the critical difference between two test results for the same material, obtained by the same operator using the same equipment on the same day in the same laboratory
9.1.2 Reproducibility—Two test results should be judged not equivalent if they differ by more than the “R” value for that material; “R” is the interval representing the difference
be-tween two test results for the same material, obtained by different operators using different equipment in different labo-ratories See Table 1
9.1.3 Any judgment in accordance with these two state-ments would have an approximate 95% probability of being correct
3 Supporting data have been filed at ASTM International Headquarters and may
be obtained by requesting Research Report RR: D35:1010.
FIG 1 Zoom of the use of silicone-coated paper
FIG 2 Shear testing
Trang 39.2 Bias—At the time of the study, there was no accepted
reference material suitable for determining the bias for this test
method, therefore no statement on bias can be made
9.3 The precision statement was determined through
statis-tical examination of results from six laboratories reporting 3
replicates each for Materials A and C, and seven laboratories
reporting 3 replicates each for Material B
10 Keywords
10.1 geomembrane; bituminous; PBGM; prefabricated seam; shear; destructive
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TABLE 1 Summary Statistics
Material Average Repeatability
Standard
Deviation
Reproducibility Standard Deviation
Repeatability Limit
Reproducibility Limit